The Burning Man Council has announced guidelines for flying RC/UAV models at burning man, with emphasis on FPV vehicles. The guidelines seem well thought out, and might be a good model for other organizations wishing to provide similar guidelines to participants.
(personal opinion) I expect we'll see more of this as quads get cheaper and easier to fly. I was at the America's Cup races on Saturday and some nitwit was flying a gopro/phantom over the crowd. (end personal opinion)
The lovely video at top is from ExperimentalAirlines.